The goal of this proposal is to test the hypothesis that RNA lassos(TM) that block the translation of TNF-alpha can decrease the clinical signs and tissue damage in experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis. RNA lassos are antisense RNAs containing an enzymatic feature that causes them to become topologically linked to a target mRNA upon hybridization. In previous work, we identified a lead lasso directed against TNF-alpha that effectively inhibits TNF-alpha secretion in a macrophage cell line and in mice. Initial experiments will compare several strategies, including electroporation, cationic lipids, and viruses, to optimize the delivery of RNA antisense lassos into myelin basic protein (MBP)-specific T cell lines. Those targeted cells will then receive stimulation to determine the effect of RNA lassos on TNF-alpha production. If the RNA lassos effectively decrease TNF-alpha, the cells will be injected into naive recipients to determine whether TNF-alpha RNA lassos decrease the severity of EAE. In addition, we will test whether in vivo administration of RNA lassos blocks the onset or ameliorates the severity of EAE. If TNF turns out not to be the best target, we will test lassos against interferon gamma. An acute toxicity study will also be performed. Commercial potential: A demonstration of efficacy in preclinical studies would lead to a clinical trail of RNA lassos alone and/or in combination with a currently approved therapeutic (e.g. Betaseron, Avonex, Copaxone). This technology may also have potential commercial applications in other conditions in which TNF-alpha contributes to inflammation and pathology, including rheumatoid arthritis and type-1 diabetes. If we demonstrate effective delivery of RNA lassos to T cells, it may also be possible to deliver lassos that block HIV gene expression and interfere with viral replication. The ultimate product would be lasso drugs for treatment of autoimmunity, an estimated market of over $6 billion per year